Approach your business partners with concepts that they can get their heads around, and try to respond to their needs.
As you start building the product, don't assume that you know all the answers. Listen to the community and adapt. We had a lot of our own ideas about how the service would evolve. Coming from PayPal and eBay, we saw YouTube as a powerful way to add video to auctions, but we didn't see anyone using our product that way, so we didn't add features to support it.
Launch your product or service before you have funding. See how people respond to it before you have a PowerPoint and business plan - have something people can use, and go from there.
I look at building business as a creative process that I enjoy.
Google has a great product. They've built a great business.